1. Field of the Invention
This invention relates to a multimetering method and means easily adaptable to existing telecommunication switching systems in which the establishment of a connection between a calling subscriber station A and a called subscriber station B is effected at least partly via a cord circuit, and in which the calling subscriber station A is allocated a call duration counter which is arranged to be stepped forward by periodic metering signals generated by a metering signal generator.
2. Description of the Prior Art
There are a number of known different types of multimetering equipment. Included in this known equipment are multimetering processes which have been triggered by mechanical means such as a clock. Such clock may operate a cam disc and thus provide pulses with the desired pulse duration and pulse interval.
Two general schemes for using metering pulses exist. The more straight forward of these involves the provision of an individual clock pulse source for each subscriber. This solution is very expensive as the number of clockpulse generators has to be very large, but it offers the advantage that the first metering pulse will then occur instantaneously and be usable. A different solution is to use a common clock pulse generator for all the subscribers connected to a single exchange, in connection with means enabling suppression of the first of the metering pulses which is apt to be incomplete and therefore the cause of a faulty count. The result is that the metering operation does not start until the second metering pulse appears (the first one which is not suppressed). With this second solution, an inexpensive exchange is obtained as only one clock pulse generator is required.
Recently a demand has arisen for multimetering also of local calls at the most busy time of the day. This demand is based on the desire to obtain a more economical use of the rather expensive telecommunication network and to obtain a more even distribution of the telecommunication traffic.
Toll metering has been employed in telecommunication networks from the beginning and therefore is designed into the exchanges and represents an integrated part of the exchanges. Local metering equipment, however, has to be developed so that it can be adapted to existing telecommunication systems in an easy and effective manner.